E. J. Kaufman1,2, D. N. Holena1 1University Of Pennsylvania,Perelman School Of Medicine,Philadelphia, PA, USA 2New York Presbyterian Hospital,Department Of Surgery,New York, NY, USA
Introduction: Non-operative management of abdominal trauma has gained acceptance in recent decades, but while ICU monitoring is a common component of this approach, there is little evidence to guide this practice. To evaluate the role of ICU admission in patients undergoing initial non-operative management of splenic injuries, we conducted a retrospective cohort study of prospectively-collected data from the Pennsylvania Trauma Outcomes Study. We hypothesized that ICU utilization would vary significantly among centers; that centers with higher-than-expected ICU utilization would have correspondingly lower mortality; and that patients admitted to the ICU would have lower risk-adjusted mortality than those admitted elsewhere.
Methods: Data from 2011-2014 for all 30 level I and II trauma centers in Pennsylvania were evaluated. Patients were excluded if they were age <17; died or were discharged in the trauma bay; or had immediate abdominal operation or angiography. Centers with ≥20 eligible patients were included. Patients transferred from the trauma bay were included at the destination center. ICU utilization was defined as ICU admission from the trauma bay or after an immediate operation. We used multivariable logistic regression to model ICU admission and mortality. We calculated observed-to-expected (O:E) center-level ICU utilization and mortality ratios with 95% confidence intervals and evaluated correlations between ICU utilization and mortality with Spearman’s rho.
Results: A total of 2,048 patients at 26 trauma centers were included (median age 41; 90.1% white; 62.9% male). Overall, 67.3% were admitted to the ICU; 63.4% of patients with grade 1-2 splenic injuries and 78.1% of those with grade 3 and above. Median injury severity score (ISS) was 16 overall; 17 for ICU patients and 12 for non-ICU patients. The final regression model for ICU utilization incorporated patient characteristics, admission physiology, and injury characteristics (grade, mechanism, and presence of concomitant abdominal, thoracic or head injuries). Model fit was good (AUC 0.74). Risk-adjusted ICU utilization rates varied from 26.8% to 95.5% among centers. Crude mortality was 4.5%; 5.8% in ICU patients and 1.9% in non-ICU patients. The final regression model for mortality incorporated surgical interventions along with the above factors, with excellent fit (AUC 0.95). ICU admission was not associated with any significant difference in mortality (4.5% vs. 4.3%, p=0.893). Significant predictors of mortality included age, ISS, operation, and admission physiology. At the center level, there was no correlation between ICU utilization and mortality O:E ratios (rs= -0.09, p=0.6645 ) or rank order (rs=- 0.10, p=0.6311).
Conclusions: Risk-adjusted ICU utilization rates for splenic trauma vary widely among trauma centers, but there is no clear relationship with mortality. Standardizing ICU admission criteria could improve resource utilization without increasing mortality.